The present invention relates to control means, in a flat knitting machine having a plurality of yarn carriers on carrier guide rails provided above and longitudinally along a needle bed, for selectively controlling the yarn carriers for movement along with the carriage.
In conventional flat knitting machines of the type having a plurality of yarn carriers movably mounted on carrier guide rails, there is usually provided on a carriage a plunger box in which are disposed a suitable number of coupling plungers, each slidable to a hooking-on or operative position relative to one of the yarn carriers for engagement therewith, so that fancy pattern knitting can be performed by selectively changing the yarn carriers to be carried along by the carriage through selective control of the coupling plungers for engagement with and disengagement from the yarn carriers. In such machines the yarn carriers are selectively moved along with the carriage through the coupling plungers, which are selectively controlled to their operative position or inoperative position relative to the yarn carriers before the carriage proceeds into a given part of its path of movement. It is also known to provide stoppers on the carrier guide rails so that the distance over which the selected yarn carrier is carried along by the carriage can be limited by selectively controlling the stoppers for displacement. Such arrangement is disclosed in U.S. Pat. No. 4,052,865 and U.S. Pat. No. 4,179,906, for example.
The present invention has for its object the provision of means for controlling the movement of yarn carriers along with a carriage which eliminate the need for stoppers, an essential feature of the prior-art arrangement, and which thereby substantially simplify the mechanical arrangement employed in the prior art machines for selective control of the yarn carriers for movement along with the carriage. More concretely, the invention consists essentially in: means for controlling the movement of yarn carriers along with a carriage in a flat knitting machine, comprising a trick location detector mounted on the carriage for detecting varying positions of the carriage on a needle bed during its movement thereon, each such position expressed in terms of the number of tricks or of needles counted from one or the other tricked end of the needle bed, a plurality of solenoids arranged in a plunger box on the carriage for individually controlling coupling plungers provided in the plunger box in the same number as the solenoids, each coupling plunger slidable to an operative position relative to one of the yarn carriers on carrier guide rails for engagement therewith, each of said solenoids connected to a solenoid drive circuit, trick position setting means adapted to memorize any predetermined signalling positions, each expressed in terms of the number of tricks counted from one or the other end of the needle bed, for selectively energizing and deenergizing the solenoids, and a control unit for controlling the solenoid drive circuit through the operation of values memorized by the trick position setting means and those detected by the trick location detector.